1. Field of the Invention
Applicant's invention relates to the field of food packaging, and more specifically, to a method and apparatus of packaging large and heavy cakes on a tray under a clear plastic cover.
2. Background Information
Presently, many cakes are packaged by placing the cake onto a base made of corrugated cardboard and then covering the cake by using a plastic see-through cover releasably fastened to the base by either using glue or by using various combinations of interlocking grooves and flange-like extensions molded into the base and the plastic see-though cover.
U.S. Pat. No. 3,770,115 for packaging container for pies discloses a method of attaching a container cover to a base by means of a groove around the edge of the inside perimeter of the cover. The groove interfaces with the horizontally extending flange located at the upper lip of the base. To fasten the cover to the base, the practitioner simply guides the horizontally extending flange into the groove until the entire perimeter of the flange snaps into place and rests snugly against the inside surface of the groove.
The container disclosed in U.S. Pat. No. 1,978,296 also uses similar means to fasten the cover to the base. In addition, U.S. Pat. No. 1,978,296 also discloses of a method for attaching the cover to the base by molding several beads or inwardly extending tabs to the cover. When the cover is affixed to the base, the beads or tabs rest snugly against the bottom side of the flange that forms the lip of the base, thereby preventing the cover from being lifted upward without the person first having to exert a certain amount of force on the cover. U.S. Pat. No. 3,837,526 also discloses similar means of attaching the cover to the base.
U.S. Pat. No. 2,246,695 uses a combination of grooves and beads to attach the cover to the base. The horizontally and outwardly extending flanges at the mouth of the base is snapped into a groove located near the bottom edge of the cover. For additional security, the edge of the cover forms an inwardly extending reinforcing bead such that, when assembled, the bead fits snugly against the bottom edge of the horizontally extending flange.
U.S. Pat. No. 3,690,902 uses yet another method to secure a cake cover to its base. Here, a horizontally and outwardly extending flange is attached to the mouth of the cover. The base, which is usually made of corrugated cardboard and which extends at least as far outward as the outer edge of the flange, is attached to the cover by means of staples.
U.S. Pat No. 3,795,360 discloses of two additional methods of attaching cover to base. In the first method, four vertical indentations, one on each face of the cover, are formed in the side walls of the cover. At precisely the same height, each indentation contains a horizontal slot having the same thickness as the horizontally outwardly extending flanges of the base. To secure the cover to the base, the flange is slipped into the horizontal slots. In the second method disclosed in U.S. Pat. No. 3,795,360, four small oval shaped indentations are located on each side of the cover so that the indentations can be slipped underneath the horizontal flanges, locking the cover to the base.
U.S. Pat. No. 4,375,862 discloses a means of attaching and detaching the cover to the base by rotating the cover clockwise or counterclockwise relative to the base. The method of attaching the cover to the base is essentially similar to the method disclosed in U.S. Pat Nos. 1,978,296 and 3,837,526, with the exception that certain parts of the base has no outward extending flange and certain portions of cover has no inward extending beads. Thus, when the portion with no outward extending flange and no inward extending bead is aligned, the cover easily fits over the base. Once the cover fits over the base, the cover can be turned clockwise or counterclockwise, locking the cover to the base by snugly fitting the bead underneath the flange.
U.S. Pat. No. 4,452,356 discloses an additional method of attaching cake cover to base. Here, food grade adhesive is applied between the outward extending flange of the cover and the corrugated cardboard cake base, thereby attaching the cake cover to the base.
Finally, U.S. Pat. No. 4,197,940 discloses of a method of attaching a cover to a base by redesigning the configuration of the base. The cover disclosed in U.S. Pat. No. 4,197,940 has a simple, outward flaring flange. The base, however, is first connected to a vertically upwardly extending flange which is then connected to a horizontally inwardly extending flange. The cover is affixed to the base by slipping the outward extending flange of the cover underneath the inwardly extending flange of the base.
The above described methods of securing the cover to the base is usually adequate for smaller cakes. However, when the cake is large and heavy, the base is simply not stiff enough to withstand the weight of the cake, and so the base tends to sag in the middle when the entire cake packaging assembly is picked up by holding on to the sides of the base. This deformation of the base tends to cause the cake cover to pop off, despite the fact that the cover is attached to the base by the various fastening means described above. The problem is not solved by holding the cake up from the middle instead of the sides. If the cake is exceptionally large or heavy, the sides may still sag even when the cake is held up from the middle. Furthermore, because of the size and the weight of the cake, holding the cake up from the middle will cause the cake to tip over if the cake holder is not careful balancing the cake. The larger the cake, the more pronounced the above problem becomes.